I ordered an item from china. I was given this tracking number RB7463636932CN but it's showing as wrong number.

The problem with this tracking Number can be explained by the following description of China Post Tracking numbers. The most common tracking number format is a combination of 13 alphabetic and numeric characters, usually starting with 2 alphabets, following by 9 digits, and ending by "CN" (e.g. RA 999 999 999 CN). Some other less common formats may also exist. Good Luck!